Saponin Fraction of Gongronema latifolium Reverses Dyslipidemia and Catalyzes Glucokinase in Lowering Blood Glucose Sugar in Streptozocin-Induced Diabetic Rats

Objective: Gongronema latifolium (GL) is a bitter tasting leaf used in Nigeria as spice in food, and as herb for the treatment of diabetes, malaria and cardiovascular disease. Research work on the anti-diabetic activities of the whole leaf extract has been carried out, but none on the saponin fraction of the leaf. A preliminary study showed that saponin-rich ethyl acetate fraction (GSF) of GL was active as an anti-diabetic agent. The aim of this study was to evaluate the sugar-lowering and anti-lipidemic effects of ethyl acetate saponin fraction (GSF) of GL in Streptozotocin-induced diabetic Albino Wistar rats.

Methods: Streptozotocin-induced diabetic rats were treated with 200 mg/kg bw and 400 mg/kg bw dose of saponin fraction of Gongronema latifolium twice daily for 21 days. The effects of GL fraction on fasting blood glucose (FBG), serum glucose, serum insulin, body weight, total cholesterol (TC), HDL-c, LDL-c, VLDL-c, triglyceride (TG) and C-peptides concentrations were determined.

Results: After 21 days treatment, GSF administration showed significantly lower FBG concentration compared to the diabetic control (DC) group. GSF increased serum insulin concentration and C-peptide levels dose-dependently. The fraction also decreased liver weight, liver cholesterol, plasma cholesterol, total cholesterol and triglyceride concentration dose-dependently. GSF 1 and 2 increased HDL-c and lowered the plasma concentration of LDL-c and VLDL-c. GSF significantly (p<0.05) increased body weights of diabetic animals time-dependently taken at 7 days interval.

Conclusion: The findings from this study suggest that GSF may provide alternative sugar-lowering effect in diabetes, and may have the potential to reverse dyslipidemia and improve body weight gain in type 2 diabetes conditions.